2010 CHEVROLET SUBURBAN automatic transmission

The vehicle has a shift stabilization feature that
adjusts the transmission shifting to the current driving
conditions in order to reduce rapid upshifts and
downshifts. This shift stabilization feature is designed to
determine, before making an upshift, if the engine is
able to maintain vehicle speed by analyzing things such
as vehicle speed, throttle position, and vehicle load.
If the shift stabilization feature determines that a current
vehicle speed cannot be maintained, the transmission
does not upshift and instead holds the current gear. In
some cases, this could appear to be a delayed shift,
however the transmission is operating normally.
The vehicle's transmission uses adaptive shift controls.
Adaptive shift controls continually compares key shift
parameters to pre-programmed ideal shifts stored in the
transmissions computer. The transmission constantly
makes adjustments to improve vehicle performance
according to how the vehicle is being used, such as
with a heavy load or when the temperature changes.
During this adaptive shift control process, shifting might
feel different as the transmission determines the best
settings.
When temperatures are very cold, the Hydra-Matic
®
6-Speed transmission's gear shifting could be delayed
providing more stable shifts until the engine warms
up. Shifts could be more noticeable with a cold
transmission. This difference in shifting is normal.M (Manual Mode):
This position is available on vehicles
with the Hydra-Matic
®6-Speed transmission. It lets
drivers select the range of gears appropriate for current
driving conditions. If the vehicle has this feature,
see Range Select Mode (Hydra-Matic
®6-Speed
transmission) later in this section.
3 (Third): This position is also used for normal driving.
It reduces vehicle speed more than D (Drive) without
using the brakes. You might choose 3 (Third) instead of
D (Drive) when driving on hilly, winding roads, when
towing a trailer, so there is less shifting between gears
and when going down a steep hill.
2 (Second): This position reduces vehicle speed even
more than 3 (Third) without using the brakes. You can
use 2 (Second) on hills. It can help control vehicle
speed as you go down steep mountain roads, but then
you would also want to use the brakes off and on.
If you manually select 2 (Second) in an automatic
transmission, the transmission will start in second gear.
You can use this feature for reducing the speed of the
rear wheels when you are trying to start the vehicle
from a stop on slippery road surfaces.
3-35

To use this feature, do the following:1. Move the shift lever to M (Manual Mode).
2. Press the plus/minus buttons, located on the steering column shift lever, to select the desired
range of gears for the current driving conditions.
When M (Manual Mode) is selected a number displays
next to the M, indicating the current gear.
This number is the highest gear that can be used.
However, the vehicle can automatically shift to lower
gears as it adjusts to driving conditions. This means
that all gears below that number are available. When
5 (Fifth) is selected, 1 (First) through 5 (Fifth) gears are
automatically shifted by the vehicle, but 6 (Sixth) cannot
be used until the plus/minus button located on the
steering column lever is used to change to the gear. Grade Braking is not available when Range Selection
Mode is active. See
Tow/Haul Mode on page 3‑38.
While using Range Selection Mode, cruise control and
the Tow/Haul mode can be used.
Notice: Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator pedal
may damage the transmission. The repair will not be
covered by the vehicle warranty. If you are stuck, do
not spin the tires. When stopping on a hill, use the
brakes to hold the vehicle in place.
Low Traction Mode
If the vehicle has the Hydra-Matic®6-Speed Automatic
Transmission, it has a Low Traction Mode that assists in
vehicle acceleration when road conditions are slippery,
such as with ice or snow. While the vehicle is at a stop,
select the second gear range using Range Selection
Mode. This will limit torque to the wheels after it detects
wheel slip, preventing the tires from spinning.
3-37

Tow/Haul Mode
The vehicle has a Tow/Haul mode. The selector button
is located on the end of the column shift lever. You can
use this feature to assist when towing or hauling a
heavy load or if there is a need to charge a battery
installed in a trailer. SeeTowing a Trailer
on page 5‑47for more information.
When Tow/Haul mode is
selected the Tow/Haul
indicator light will
come on.
The Tow/Haul mode works with the Autoride
®feature,
if the vehicle has this, to enhance the ride when
trailering or with a loaded vehicle. See Autoride
®on
page 5‑46.
Grade Braking (Hydra-Matic®6-Speed
Automatic Transmission)
The Grade Braking shift modes can be activated by
pressing the button on the end of the shift control lever.
While in Range Selection Mode , Grade Braking is
deactivated allowing the driver to select a desired range
of gears.
Grade Braking is only active while the Tow/Haul Mode
is selected and you are not in the Range Selection
Mode. See “Tow/Haul Mode listed previously and
Automatic Transmission Operation
on page 3‑32for more information on the Range Selection Mode.
3-38

Grade Braking assists in maintaining desired
vehicle speeds when driving on downhill grades by
automatically implementing a shift schedule that utilizes
the engine and transmission to slow the vehicle. This
reduces wear on the braking system and increases
control of the vehicle. Grade Braking monitors vehicle
speed, acceleration, engine torque and brake pedal
usage. Using this information, it detects when the truck
is on a downhill grade and the driver desires to slow the
vehicle by pressing the brake.
Also seeTowing a Trailer
on page 5‑47for more
information.
Cruise Grade Braking (Hydra-Matic®
6-Speed Automatic Transmission)
Cruise Grade Braking assists when driving on a
downhill grade. It maintains vehicle speed by
automatically implementing a shift schedule that uses
the engine and the transmission to slow the vehicle.
Cruise Grade Braking operates while Cruise Control is
engaged in Tow/Haul mode to assist in maintaining
vehicle speed under loaded vehicle conditions.
It utilizes vehicle acceleration and deviation from
desired speed to determine the correct gear for the
operating condition. If vehicle speed is above the
desired speed the transmission will downshift to slow
the vehicle. If vehicle speed is near or below desired
speed the trans will upshift, allowing vehicle speed to
increase. While in the Range Select Mode (RSM) mode, Cruise
Grade Braking is not available.
See
Automatic Transmission Operation on page 3‑32.
Four-Wheel Drive (Two Speed
Automatic Transfer Case)
If the vehicle has four-wheel drive, you can send the
engine's driving power to all four wheels for extra
traction. Read the following before using four-wheel
drive.
Notice: Driving on clean, dry pavement in
Four-Wheel Drive High or Four-Wheel Drive Low for
an extended period of time may cause premature
wear on your vehicle's powertrain. Do not drive on
clean, dry pavement in Four-Wheel Drive High or
Four-Wheel Drive Low for extended periods of time.
While driving on clean dry pavement and during tight
turns, you may experience a vibration in the steering
system.
The vehicle has StabiliTrak
®. Shifting into
Four-Wheel-Drive Low will turn Traction Control and
StabiliTrak
®off. See StabiliTrak®System on page 5‑6.
Front Axle
The front axle engages and disengages automatically
when you shift the transfer case. Some delay for the
axle to engage or disengage is normal.
3-39

The vehicle has StabiliTrak®. Shifting into
Four-Wheel-Drive Low will turn Traction Control
and StabiliTrak
®off. See StabiliTrak®Systemon
page 5‑6.
{WARNING:
Shifting the transfer case to N (Neutral) can cause
the vehicle to roll even if the transmission is in
P (Park). You or someone else could be seriously
injured. Be sure to set the parking brake before
placing the transfer case in N (Neutral). See
Parking Brake on page 3‑46.
N (Neutral): Shift the vehicle's transfer case to
N (Neutral) only when towing the vehicle. See
Recreational Vehicle Towing
on page 5‑40or Towing
Your Vehicleon page 5‑40for more information.
If the SERVICE 4 WHEEL DRIVE message stays on,
you should take the vehicle to your dealer for service.
See “SERVICE 4 WHEEL DRIVE message” underDIC
Warnings and Messages on page 4‑61.
Shifting Into Four-Wheel Drive High or
AUTO (Automatic Four-Wheel Drive)
Turn the knob to the Four-Wheel High or AUTO
position. This can be done at any speed, except when
shifting from Four-Wheel Drive Low. The indicator light
will flash while shifting. It will remain on when the shift is
completed.
Shifting Into Two-Wheel Drive High
Turn the knob to the Two-Wheel High position. This
can be done at any speed, except when shifting from
Four-Wheel Drive Low.
See shifting out of Four-Wheel Drive Low later in this
section for more information.
Shifting Into Four-Wheel Drive Low
When Four-Wheel Low is engaged, vehicle speed
should be kept below 45 mph (72 km/h). Extended
high-speed operation in 4L may damage or shorten
the life of the drivetrain.
To shift to the Four-Wheel Drive Low position, the
ignition must be in ON/RUN and the vehicle must
be stopped or moving less than 3 mph (5 km/h) with
the transmission in N (Neutral). The preferred method
for shifting into Four-Wheel Drive Low is to have
the vehicle moving 1 to 2 mph (1.6 to 3.2 km/h).
3-41

4. Release the parking brake prior to moving thevehicle.
Notice: Shifting the transmission into gear before
the Four-Wheel Drive Low indicator light has
stopped flashing could damage the transfer case.
To help avoid damaging the vehicle, always wait for
the Four-Wheel Drive Low indicator light to stop
flashing before shifting the transmission into gear.
5. Start the engine and shift the transmission to the desired position.
Excessively shifting the transfer case into or out of the
different modes may cause the transfer case to enter
the shift protection mode. This will protect the transfer
case from possible damage and will only allow the
transfer case to respond to one shift per 10 seconds.
The transfer case may stay in this mode for up to
three minutes.Four-Wheel Drive (Single Speed
Automatic Transfer Case)
If the vehicle has four-wheel drive, you can send the
engine's driving power to all four wheels for extra
traction. Read the following before using four-wheel
drive.
Notice: Driving on clean, dry pavement in
Four-Wheel Drive High for an extended period of
time may cause premature wear on the vehicle's
powertrain. Do not drive on clean, dry pavement in
Four-Wheel Drive High for extended periods of time.
While driving on clean dry pavement and during tight
turns, you may experience a vibration in the steering
system.
Front Axle
The front axle engages and disengages automatically
when you shift the transfer case. Some delay for the
axle to engage or disengage is normal.
3-44

Running the Vehicle While Parked
It is better not to park with the engine running. But if you
ever have to, here are some things to know.
{WARNING:
Idling a vehicle in an enclosed area with poor
ventilation is dangerous. Engine exhaust may
enter the vehicle. Engine exhaust contains
Carbon Monoxide (CO) which cannot be seen
or smelled. It can cause unconsciousness and
even death. Never run the engine in an enclosed
area that has no fresh air ventilation. For more
information, seeEngine Exhaust on page 3‑50.
{WARNING:
It can be dangerous to get out of the vehicle if the
automatic transmission shift lever is not fully in
P (Park) with the parking brake firmly set. The
vehicle can roll. Do not leave the vehicle when the
engine is running unless you have to. If you have
(Continued)
WARNING: (Continued)
left the engine running, the vehicle can move
suddenly. You or others could be injured. To be
sure the vehicle will not move, even when you
are on fairly level ground, always set the parking
brake and move the shift lever to P (Park).
{WARNING:
If the vehicle has a four-wheel drive transfer
case with a N (Neutral) position, and the transfer
case is in N (Neutral), the vehicle may roll, even
if the automatic transmission shift lever is in
P (Park). So, be sure the transfer case is in a
drive gear—not in N (Neutral). Always set the
parking brake.
Follow the proper steps to be sure the vehicle will not
move. See Shifting Into Park on page 3‑47.
If pulling a trailer, see Towing a Trailer on page 5‑47.
3-51

When the headlamps are turned on while the vehicle is
on, the headlamps will turn off automatically 10 minutes
after the ignition is turned off. When the headlamps are
turned on while the vehicle is off, the headlamps will
stay on for 10 minutes before automatically turning off
to prevent the battery from being drained. Turn the
headlamp control to off and then back to the headlamp
on position to make the headlamps stay on for an
additional 10 minutes.
Headlamps on Reminder
A reminder chime will sound when the headlamps or
parking lamps are manually turned on and the ignition is
off and a door is open. To disable the chime, turn the
light off.
Daytime Running Lamps (DRL)
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the day.
Fully functional daytime running lamps are required on
all vehicles first sold in Canada.
The DRL system comes on when the following
conditions are met:
.The ignition is on.
.The exterior lamps control is in AUTO.
.The engine is running.
.The light sensor determines it is daytime.When the DRL system is on, only the DRL lamps are
on. The taillamps, sidemarker, instrument panel lights,
and other lamps will not be on.
When it begins to get dark, the automatic headlamp
system switches from DRL to the headlamps.
To turn off the DRL lamps, turn the exterior lamps
control to the OFF position and then release. For
vehicles first sold in Canada, the transmission must be
in the P (Park) position, before the DRL lamps can be
turned off.
Automatic Headlamp System
When it is dark enough outside, the automatic
headlamp system turns on the headlamps at the normal
brightness, along with the taillamps, sidemarker, parking
lamps, and the instrument panel lights. The radio lights
will also be dim.
To turn off the automatic headlamp system, turn the
exterior lamps switch to the off position and then
release it. For vehicles first sold in Canada, the
transmission must be in the P (Park) position, before
the automatic headlamp system can be turned off.
The vehicle has a light sensor located on the top of the
instrument panel in the defroster grille that regulates
when the automatic headlamps turn on. Do not cover
the sensor or the headlamps will come on whenever the
ignition is on.
4-12